Determine how many solutions exist for the system of equations. ${-5x+y = 10}$ ${5x-y = -5}$
Answer: Convert both equations to slope-intercept form: ${-5x+y = 10}$ $-5x{+5x} + y = 10{+5x}$ $y = 10+5x$ ${y = 5x+10}$ ${5x-y = -5}$ $5x{-5x} - y = -5{-5x}$ $-y = -5-5x$ $y = 5+5x$ ${y = 5x+5}$ Just by looking at both equations in slope-intercept form, what can you determine? ${y = 5x+10}$ ${y = 5x+5}$ Both equations have the same slope with different y-intercepts. This means the equations are parallel. ${1}$ ${2}$ ${3}$ ${4}$ ${5}$ ${6}$ ${7}$ ${8}$ ${9}$ ${\llap{-}2}$ ${\llap{-}3}$ ${\llap{-}4}$ ${\llap{-}5}$ ${\llap{-}6}$ ${\llap{-}7}$ ${\llap{-}8}$ ${\llap{-}9}$ ${1}$ ${2}$ ${3}$ ${4}$ ${5}$ ${6}$ ${7}$ ${8}$ ${9}$ ${\llap{-}2}$ ${\llap{-}3}$ ${\llap{-}4}$ ${\llap{-}5}$ ${\llap{-}6}$ ${\llap{-}7}$ ${\llap{-}8}$ ${\llap{-}9}$ Parallel lines never intersect, thus there are NO SOLUTIONS.